import java.util.concurrent.Semaphore;

public class Test4 {

    static int count = 0;
    public static void main(String[] args) throws InterruptedException {
        Semaphore semaphore = new Semaphore(1);
        Thread t1 = new Thread(()->{
            try {
                for (int i = 0; i < 50000; i++) {
                    semaphore.acquire();//计数器+1
                    count++;
                    semaphore.release();//计数器-1
                }
            } catch (InterruptedException e) {
                throw new RuntimeException(e);
            }
        });
        Thread t2 = new Thread(()->{
            try {
                for (int i = 0; i < 50000; i++) {
                    semaphore.acquire();//加锁
                    count++;
                    semaphore.release();//解锁
                }
            } catch (InterruptedException e) {
                throw new RuntimeException(e);
            }
        });
        t1.start();
        t2.start();
        t1.join();
        t1.join();
        System.out.println(count);
    }

    public static void main1(String[] args) throws InterruptedException {
        Semaphore semaphore = new Semaphore(5);//设置计数器的容量
        int i=0;
        semaphore.acquire();
        System.out.println("P操作"+": "+i++);
        semaphore.acquire();
        System.out.println("P操作"+": "+i++);
        semaphore.acquire();
        System.out.println("P操作"+": "+i++);
        semaphore.acquire();
        System.out.println("P操作"+": "+i++);
        semaphore.acquire();
        System.out.println("P操作"+": "+i++);

        semaphore.release();
        System.out.println("V操作");

        semaphore.acquire();
        System.out.println("P操作"+": "+i++);

    }
}
